This invention relates to a process for connection of supports and a support system best suited not only for formation of a temporary scaffolding such as a prefabricated scaffolding or a temporary system such as a panel support but also for construction of a relatively long-lasting structure such as a truss-type pillar, tower, etc.
For formation of a temporary scaffolding such as a prefabricated scaffolding or a temporary system such as a panel support, etc., a support system is employed.
As the support system to be used in such situations, there has been provided a support system comprising simple pipes, as main members, and clamps as connecting means.
In recent years, however, there have been proposed inventive devices according to, for instance, Japanese Patent Publication Nos. 54-3407 (1979) and 58-15587 (1983), as a substitute for the above-mentioned system.
The invention proposals, in principle, comprise lontitudinal members and transverse members (and diagonal members) connected thereto.
The longitudinal member comprises a steel pipe member, as a main body, and a plurality of annular flanges having an appropriate width and welded to the outer peripheral surface of the steel pipe member at regular intervals along the axial direction of the pipe member.
In the inventive proposal according to the above-mentioned Japanese Patent Publication No. 54-3407 (1929), the flanges are each provided with substantially sectorial engaging portions constituted of cutouts through the material thickness of the flange, at arbitrary angular intervals, for instance, four engaging portions at 90.degree. intervals.
On the other hand, the transverse members (and diagonal members) each comprise an appropriate length of steel pipe member, as a main body, and joint shoes fixed to both ends of the pipe member.
The joint shoe comprises a pair of wall bodies, which are disposed to face the upper and lower surfaces of the flange, with a wedge insertion hole provided at a central portion of each of the wall bodies.
A wedge is driven into the wedge insertion holes. When the wedge is driven into the wedge insertion holes, one side edge of the wedge is pressed against the aperture edges of the wedge insertion holes, while the other side edge is pressed against the inner periphery of the cutout in the flange.
In this case it is possible, according to the inventive proposal under consideration, to achieve fixed connection of the wall bodies at the tip of the joint shoe with the engaging portion of the flange.
Therefore, when the longitudinal members comprising the flanges are made to be columnar membres whereas the transverse members provided with the joint hoes are made to be horizontal members, with the diagonal members made to be connecting members such as brace members, and pluralities of the two types of members are assmbled by connecting them together using wedges, it is possible to form a desired temporary scaffolding such as a prefabricated scaffolding or a desired temporary system such as a panel support, in an arbitrary size.
On the other hand, in the inventive device according to the above-mentioned Japanese Patent Publication No. 58-15587 (1983), the flange is provided with a plinth-like supporting piece raised on an outer peripheral portion of the flange along the circumferencial direction, whereas the joint shoe is provided with a tip hook portion to be disengageably engaged with the supporting piece and is provided with a wedge insertion hole on the base end side thereof.
According to the inventive device, therefore, when the tip hook portion of the joint shoe is engaged with the supporting piece of the flange and wedging is conducted, it is possible to connect the transverse member to the columnar member extending from an arbitray direction relative to the columnar member.
In the inventive device according to the above-mentioned Japanese Patent Publication No. 54-3407 (1979), however, there is a limit to the number of cutouts provided as engaging portions in the flange, and the fitting positions of the joint shoe is limited by the number of the cutouts. Therefore, the number of the transverse members capable of being fitted is also limited.
In addition, a plurality of the flanges provided with the cutouts as engaging portions are fixedly arranged on the outer periphery of the columnar member at appropriate intervals along the vertical direction. There is therefore a problem that the cutouts formed in the flanges spaced apart vertically must be in register with each other, as viewed vertically.
Besides, in the inventive devies according to the above-mentioned Japanese Patent Publication Nos. 54-3407 (1979) and 58-15587 (1983), the joint shoes are engaged only with the flanges. When a vertical load is exerted on the transverse member, the stress is concentrated on the flange side, and there is a possibility of the flange being broken and the transverse member being disconnected from the longitudinal member.
Moreover, in the inventive devices according to the proposals mentioned above, the wedge is driven into the wedge insertion hole bored in the joint shoe so that one side edge of the wedge is pressed against the aperture edge of the wedge insertion hole whereas the other side edge of the wedge is pressed against the flange, as mentioned above.
In such conventional inventive devices as mentioned above, therefore, there is a tendency of the flanges being damaged upon driving of the wedges, leading to difficulties in repeated use of the longitudinal members provided with the flanges.